DOI: 10.1016/j.foreco.2016.01.017
Scopus记录号: 2-s2.0-84956656127
论文题名: Spatial and temporal trends of drought effects in a heterogeneous semi-arid forest ecosystem
作者: Assal T.J. ; Anderson P.J. ; Sibold J.
刊名: Forest Ecology and Management
ISSN: 0378-1127
出版年: 2016
卷: 365 起始页码: 137
结束页码: 151
语种: 英语
英文关键词: Drought effects
; Forest-shrubland ecotone
; Landsat time-series
; Rocky Mountain forests
; Temporal trend analysis
Scopus关键词: Drought
; Ecology
; Ecosystems
; Remote sensing
; Time series
; Time series analysis
; Water content
; Canopy water contents
; Landsat time series
; Long-term perspective
; Normalized difference moisture indices
; Rocky Mountains
; Shrublands
; Spatial and temporal trends
; Temporal trends
; Forestry
英文摘要: Drought has long been recognized as a driving mechanism in the forests of western North America and drought-induced mortality has been documented across genera in recent years. Given the frequency of these events are expected to increase in the future, understanding patterns of mortality and plant response to severe drought is important to resource managers. Drought can affect the functional, physiological, structural, and demographic properties of forest ecosystems. Remote sensing studies have documented changes in forest properties due to direct and indirect effects of drought; however, few studies have addressed this at local scales needed to characterize highly heterogeneous ecosystems in the forest-shrubland ecotone. We analyzed a 22-year Landsat time series (1985-2012) to determine changes in forest in an area that experienced a relatively dry decade punctuated by two years of extreme drought. We assessed the relationship between several vegetation indices and field measured characteristics (e.g. plant area index and canopy gap fraction) and applied these indices to trend analysis to uncover the location, direction and timing of change. Finally, we assessed the interaction of climate and topography by forest functional type. The Normalized Difference Moisture Index (NDMI), a measure of canopy water content, had the strongest correlation with short-term field measures of plant area index (R2 = 0.64) and canopy gap fraction (R2 = 0.65). Over the entire time period, 25% of the forested area experienced a significant (p-value < 0.05) negative trend in NDMI, compared to less than 10% in a positive trend. Coniferous forests were more likely to be associated with a negative NDMI trend than deciduous forest. Forests on southern aspects were least likely to exhibit a negative trend while north aspects were most prevalent. Field plots with a negative trend had a lower live density, and higher amounts of standing dead and down trees compared to plots with no trend. Our analysis identifies spatially explicit patterns of long-term trends anchored with ground based evidence to highlight areas of forest that are resistant, persistent or vulnerable to severe drought. The results provide a long-term perspective for the resource management of this area and can be applied to similar ecosystems throughout western North America. © 2016 Published by Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/65036
Appears in Collections: 影响、适应和脆弱性
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作者单位: U.S. Geological Survey (USGS), Fort Collins Science Center, 2150 Centre Avenue, Fort Collins, CO, United States; Graduate Degree Program in Ecology, Colorado State University, 1401 Campus Delivery, Fort Collins, CO, United States; Department of Anthropology, Colorado State University, 1787 Campus Delivery, Fort Collins, CO, United States
Recommended Citation:
Assal T.J.,Anderson P.J.,Sibold J.. Spatial and temporal trends of drought effects in a heterogeneous semi-arid forest ecosystem[J]. Forest Ecology and Management,2016-01-01,365